U.S. patent application number 14/246184 was filed with the patent office on 2014-11-13 for dedicated channel establishment method for high speed data transmission in railway wireless sensor network.
This patent application is currently assigned to Electronics and Telecommunications Research Institute. The applicant listed for this patent is Electronics and Telecommunications Research Institute. Invention is credited to Jae Hoon KIM, Young Il KIM, Geon Min YEO.
Application Number | 20140336850 14/246184 |
Document ID | / |
Family ID | 51865375 |
Filed Date | 2014-11-13 |
United States Patent
Application |
20140336850 |
Kind Code |
A1 |
KIM; Young Il ; et
al. |
November 13, 2014 |
DEDICATED CHANNEL ESTABLISHMENT METHOD FOR HIGH SPEED DATA
TRANSMISSION IN RAILWAY WIRELESS SENSOR NETWORK
Abstract
Disclosed is a railway wireless sensor network system. The
railway wireless sensor network system includes a plurality of
sensors which are included in a railway vehicle and measure an
operation state of the railway vehicle in real time, a plurality of
routers which receive information on the measured operation state
through a dedicated channel with each sensor, and a gateway which
receives information on the operation state through a dedicated
channel between the routers, and periodically transmits information
on the received operation state to a railway vehicle control
center.
Inventors: |
KIM; Young Il; (Daejeon,
KR) ; YEO; Geon Min; (Daejeon, KR) ; KIM; Jae
Hoon; (Goyang-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Electronics and Telecommunications Research Institute |
Daejeon-si |
|
KR |
|
|
Assignee: |
Electronics and Telecommunications
Research Institute
Daejeon-si
KR
|
Family ID: |
51865375 |
Appl. No.: |
14/246184 |
Filed: |
April 7, 2014 |
Current U.S.
Class: |
701/19 |
Current CPC
Class: |
B61L 27/0005 20130101;
B61L 15/0027 20130101 |
Class at
Publication: |
701/19 |
International
Class: |
B61L 27/00 20060101
B61L027/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 9, 2013 |
KR |
10-2013-0052780 |
Claims
1. A railway wireless sensor network system comprising: a plurality
of sensors which are included in a railway vehicle and measure an
operation state of the railway vehicle in real time; a plurality of
routers which receive information on the measured operation state
through a dedicated channel with each sensor; and a gateway which
receives information on the operation state through a dedicated
channel between the routers, and periodically transmits information
on the received operation state to a railway vehicle control
center.
2. The railway wireless sensor network system of claim 1, wherein
the router sets the dedicated channel with the sensor and the
dedicated channel between the routers by utilizing a
contention-free period of a medium access control (MAC) frame.
3. The railway wireless sensor network system of claim 1, wherein,
if a token issuing message is received from the gateway, the router
sets the dedicated channel with the sensor and the dedicated
channel between the routers.
4. The railway wireless sensor network system of claim 3, wherein
the token issuing message includes a number of the router, numbers
of sensors which are connected to the router, and information on a
use period of the dedicated channel.
5. The railway wireless sensor network system of claim 1, wherein
the gateway sets a dedicated channel with a router of a lowest
hierarchy through the dedicated channel between the routers.
6. The railway wireless sensor network system of claim 1, wherein
the gateway integrates dedicated channels between the plurality of
routers and controls the integrated dedicated channels.
7. The railway wireless sensor network system of claim 1, wherein,
when setting the dedicated channel between the routers, the router
encapsulates a dedicated channel path between routers of a lower
hierarchy of the router, and transmits the encapsulated path in a
tunneling scheme.
8. The railway wireless sensor network system of claim 1, wherein
the gateway binds a dedicated channel path between routers of a
lower hierarchy of the router to the dedicated channel between the
routers.
9. The railway wireless sensor network system of claim 1, wherein,
if information on the operation state is not received from the
router until a timer is terminated by operating the timer when
issuing a token, the gateway transmits a path canceling message to
the router so as to cancel the dedicated channel with the
router.
10. The railway wireless sensor network system of claim 1, wherein,
if the token issuing message is received from the gateway, the
router operates a timer, and if information on the operation state
is not received until the timer is terminated, the router cancels
the dedicated channel between sensors, which are connected to the
router, based on a token returning message which has been received
from the gateway.
11. The railway wireless sensor network system of claim 1, wherein
information on the operation state is information on temperatures
and vibrations of bearings which are positioned at axles of the
railway vehicle.
12. A method of operating a gateway in a railway wireless sensor
network, the method comprising: transmitting a token issuing
message to a router; receiving information on an operation state of
a railway vehicle, which is measured in real time by a sensor
included in the railway vehicle, from the router, through a
dedicated channel which is set according to the token issuing
message; and transmitting the received information on the operation
state, periodically, to a railway vehicle control center.
13. The method of claim 12, wherein the router sets a dedicated
channel with the sensor and a dedicated channel between the routers
by utilizing a contention-free period of a medium access control
(MAC) frame.
14. The method of claim 12, wherein, if a token issuing message is
received from the gateway, the router sets the dedicated channel
with the sensor and the dedicated channel between the routers.
15. The method of claim 14, wherein the token issuing message
includes a number of the router, numbers of sensors which are
connected to the router, and information on a use period of the
dedicated channel.
16. The method of claim 12, further comprising: integrating
dedicated channels between a plurality of routers and controlling
the integrated dedicated channels after transmitting the token
issuing message.
17. The method of claim 12, wherein, when setting the dedicated
channel between the routers, the router encapsulates a dedicated
channel path between routers of a lower hierarchy of the router,
and transmits the encapsulated path in a tunneling scheme.
18. The method of claim 12, further comprising: binding a dedicated
channel path between routers of a lower hierarchy of the router to
the dedicated channel between the routers after transmitting the
token issuing message.
19. The method of claim 12, after transmitting the token issuing
message, further comprising: operating a timer; and canceling the
dedicated channel with the router by transmitting a path canceling
message to the router if information on the operation state is not
received from the router until the timer is terminated.
20. A method of operating a router in a railway wireless sensor
network, the method comprising: receiving a token issuing message
from a gateway; setting a dedicated channel with a sensor included
in a railway vehicle and a dedicated channel with routers according
to the token issuing message; receiving information on an operation
state of the railway vehicle, which is measured by the sensor, from
the sensor, through the dedicated channel with the sensor; and
transmitting information on the received operation state to a
gateway through the dedicated channel between the routers.
Description
[0001] Priority to Korean patent application number 2013-0052780
filed on May 9, 2013, the entire disclosure of which is
incorporated by reference herein, is claimed.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method of allocating a
wireless channel between a wireless sensor and a router and a
wireless channel between routers to enhance transmission efficiency
of measuring information and a method thereof in a safety
management technology of railway facilities where heat generation
state of a bogie and operation state of parts included in a railway
vehicle under operation are measured in real time for safety of the
railway vehicle.
[0004] 2. Discussion of the Related Art
[0005] Heating generation state and vibration state of axles of a
railway vehicle need to be measured in real time in order to
promptly repair the vehicle at the time of occurrence of an
abnormal state for safety of the railway vehicle.
[0006] To this end, for example, Korean Patent Publication No.
10-2010-0067999 (published on Jun. 22, 2010) "automatic railway
vehicle examination apparatus" discloses sensing and systematically
managing an abnormal operation of the body of a railway vehicle as
well as a wheel and a pantograph.
[0007] Currently, a scheme of installing a device for measuring
generated heat of a railway vehicle in a non-contacting manner at a
railroad, and transmitting measured temperature information to a
maintenance center, is used. However, this scheme fails to play an
appropriate role due to inaccuracy of measurement and limitation in
the number of times measured, and thus accidents are not prevented
in advance and trains have been derailed, thereby failing to
maintain safe driving.
[0008] Hence, there is a need of a method for accurately measuring
the state of a railway vehicle under operation and transmitting the
measured result to a railway vehicle control center in real
time.
SUMMARY OF THE INVENTION
[0009] An object of the present invention is to provide a method of
setting and operating a dedicated channel for high speed
transmission of data in a railway wireless sensor network capable
of accurately measuring the state of a railway vehicle and
transmitting the measured result to a railway vehicle control
center in real time.
[0010] Another object of the present invention is to provide a
method of setting and operating a dedicated channel for high speed
transmission of data in a railway wireless sensor network capable
of transmitting information on the operation state of a railway
vehicle, which is operated in a poor communication environment, at
high speed.
[0011] In accordance with an aspect of the present invention, a
railway wireless sensor network system includes a plurality of
sensors which are included in a railway vehicle and measure an
operation state of the railway vehicle in real time, a plurality of
routers which receive information on the measured operation state
through a dedicated channel with each sensor, and a gateway which
receives information on the operation state through a dedicated
channel between the routers, and periodically transmits information
on the received operation state to a railway vehicle control
center.
[0012] The router may set the dedicated channel with the sensor and
the dedicated channel between the routers by utilizing a
contention-free period of a medium access control (MAC) frame.
[0013] If a token issuing message is received from the gateway, the
router may set the dedicated channel with the sensor and the
dedicated channel between the routers.
[0014] The token issuing message may include a number of the
router, numbers of sensors which are connected to the router, and
information on a use period of the dedicated channel.
[0015] The gateway may set a dedicated channel with a router of a
lowest hierarchy through the dedicated channel between the
routers.
[0016] The gateway may integrate dedicated channels between the
plurality of routers to control the integrated dedicated
channels.
[0017] When setting the dedicated channel between the routers, the
router may encapsulate a dedicated channel path between routers of
a lower hierarchy of the router, and transmit the encapsulated path
in a tunneling scheme.
[0018] The gateway may bind a dedicated channel path between
routers of a lower hierarchy of the router to the dedicated channel
between the routers.
[0019] If information on the operation state is not received from
the router until a timer is terminated by operating the timer when
issuing a token, the gateway may transmit a path canceling message
to the router so as to cancel the dedicated channel with the
router.
[0020] If the token issuing message is received from the gateway,
the router may operate a timer, and if information on the operation
state is not received until the timer is terminated, the router may
cancel the dedicated channel between sensors, which are connected
to the router, based on a token returning message which has been
received from the gateway.
[0021] Information on the operation state may be information on
temperatures and vibrations of bearings which are positioned at
axles of the railway vehicle.
[0022] In accordance with another aspect of the present invention,
a method of operating a gateway in a railway wireless sensor
network includes transmitting a token issuing message to a router,
receiving information on an operation state of a railway vehicle,
which is measured in real time by a sensor included in the railway
vehicle, from the router, through a dedicated channel which is set
according to the token issuing message, and transmitting the
received information on the operation state, periodically, to a
railway vehicle control center.
[0023] In accordance with yet another aspect of the present
invention, a method of operating a router in a railway wireless
sensor network includes receiving a token issuing message from a
gateway, setting a dedicated channel with a sensor included in a
railway vehicle and a dedicated channel with routers according to
the token issuing message, receiving information on an operation
state of the railway vehicle, which is measured by the sensor, from
the sensor, through the dedicated channel with the sensor, and
transmitting information on the received operation state to a
gateway through the dedicated channel between the routers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a diagram illustrating a railway wireless sensor
network system, according to an embodiment of the present
invention;
[0025] FIG. 2 is a diagram illustrating an operation path of a
railway wireless sensor network system according to the present
invention;
[0026] FIG. 3 is a diagram illustrating a structure of a medium
access control (MAC) frame of IEEE 802.15.4;
[0027] FIG. 4 is a diagram illustrating dedicated channel tunneling
between routers, according to an embodiment of the present
invention;
[0028] FIG. 5 is a diagram illustrating a dedicated channel path
setting MAC message, according to an embodiment of the present
invention;
[0029] FIG. 6 is a flowchart illustrating operation of a gateway,
according to an embodiment of the present invention; and
[0030] FIG. 7 is a flowchart illustrating operation of a router,
according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0031] Hereinafter, embodiments of the present invention will be
described in detail with reference to the accompanying drawings so
that they can be readily implemented by those skilled in the
art.
[0032] Hereinafter, some embodiments of the present invention are
described in detail with reference to the accompanying drawings in
order for a person having ordinary skill in the art to which the
present invention pertains to be able to readily implement the
invention. It is to be noted the present invention may be
implemented in various ways and is not limited to the following
embodiments. Furthermore, in the drawings, parts not related to the
present invention are omitted in order to clarify the present
invention and the same or similar reference numerals are used to
denote the same or similar elements.
[0033] Terms such as "including," "having," "consist of" may be
intended to indicate a plurality of components unless the terms are
used with the term "only". Terms such as "unit" refer to a unit for
processing at least one function or operation, and may be
implemented as hardware, software, or a combination of hardware and
software.
[0034] FIG. 1 is a diagram illustrating a railway wireless sensor
network system, according to an embodiment of the present
invention.
[0035] Referring to FIG. 1, the railway wireless sensor network
system according to the present invention may include a plurality
of sensors 111, 112, 113, 121, 122, 123, 131, 132, 141, and 142, a
plurality of routers 110, 120, 130, and 140, and at least one
gateway 150.
[0036] Respective sensors 111, 112, 113, 121, 122, 123, 131, 132,
141, and 142 are included in a railway vehicle, and may be
connected to routers 110, 120, 130, and 140 having good electric
wave receiving intensity. Referring to FIG. 1, for example, a first
sensor 111, a second sensor 112, and a third sensor 113 are
connected to a first router 110, a fourth sensor 121, a fifth
sensor 122, and a sixth sensor 123 are connected to a second router
120, a seventh sensor 131 and a eighth sensor 132 are connected to
a third router 130, and a ninth sensor 141 and a tenth sensor 142
are connected to a fourth router 140.
[0037] The respective sensors 111, 112, 113, 121, 122, 123, 131,
132, 141, and 142 measure the operation status of the railway
vehicle and transmit information on the measured operation status
to the routers 110, 120, 130, and 140 in real time. For example,
the respective sensors 111, 112, 113, 121, 122, 123, 131, 132, 141,
and 142 periodically measure the temperature (T) and vibration (V)
of the driving unit (e.g., bearings on axles) of the railway
vehicle, and measured values to the connected router 110, 120, 130,
or 140.
[0038] Each router 110, 120, 130, and 140 may transmit information,
which is received from respective sensors 111, 112, 113, 121, 122,
123, 131, 132, 141, and 142, to the gateway 150 via the routers
which are positioned at another hierarchy.
[0039] The gateway 150 may transmit the information, which is
received from the routers 110, 120, 130, and 140, to a railway
vehicle control center 160 so that the railway vehicle control
center 160 may manage safe driving of the railway vehicle based on
the sensor measurement value. At this time, various wireless
connection technologies (e.g., IEEE802.15.4/Zigbee) may be used in
wireless transmission sections between a sensor and a router,
between a router and a gateway, and between routers.
[0040] FIG. 2 is a diagram illustrating an operation path of a
railway wireless sensor network system according to the present
invention. Hereinafter, referring to FIG. 2, the first sensor 111,
the second sensor 112, and the third sensor 113 are connected to
the first router 110, the fourth sensor 121, the fifth sensor 122,
and the sixth sensor 123 are connected to the second router 120,
the seventh sensor 131 and the eighth sensor 132 are connected to
the third router 130, and the ninth sensor 141 and the tenth sensor
142 are connected to the fourth router 140.
[0041] The gateway 150 issues a token for periodically transmitting
measured information to sensors which are connected to a specific
router. For example, the gateway 150 may transmit a first token to
the first router 110 to receive information (measured values) of
the first sensor 111, the second sensor 121, and the third sensor
131. The first router 110, which has received the first token, may
form dedicated channels 211, 212, and 213 respectively with the
connected sensors, i.e., the first sensor 111, the second sensor
112, and the third sensor 113, and may also set a dedicated channel
210 between the gate 140 and the first router 110 itself. Likewise,
the information, which is measured in the sensor through the
generated dedicated channel, may be transmitted at high speed
without a transmission delay which is generated in the process of
accessing a channel.
[0042] Further, if a second token is received from the gateway 150,
the second router 120 may form dedicated channels 221, 222, and 223
with the sensors 121, 122, and 123 which are connected to the
second router 120 itself, and may also set the dedicated channel
220 between the second router 120 itself and the first router 110
and the dedicated channel 210 between the gateway 150 and the first
router 110. At this time, when the dedicated channel 210 between
the gateway 150 and the first router 110 has been set, the setting
is omitted. Likewise, the third router 130 and the fourth router
140 may also set dedicated channels with the connected sensors 131,
132, 141, and 142.
[0043] Further, when the gateway 150 does not want dedicated
channel type communication with the sensors in a specific router or
the wireless channel state is deteriorated, the procedure of
returning the token may be performed. For example, when the gateway
150 returns the third token, the setting of the dedicated channel
with the sensors 131 and 132, which have been connected to the
third router 130, is cancelled, and the dedicated channel 230
between the second router 120 and the third router 130 may also be
cancelled. At this time, when the fourth router 140 periodically
communicates with the sensors 141 and 142 using a dedicated channel
scheme, the dedicated channel 230 between the second router and the
third router 130 and the dedicated channel between the third router
120 and the fourth router 130 may be maintained. To this end, the
dedicated channels 210, 220, 230, and 240 between routers may be
used by tunneling information which is transmitted to respective
routers. Hence, the gateway 150 may control sensors, which are
connected to some specific routers, among a plurality of routers
110, 120, 130, and 140, independently from other routers.
[0044] FIG. 3 is a diagram illustrating a structure of a medium
access control (MAC) frame of IEEE 802.15.4.
[0045] As illustrated in FIG. 3, the MAC frame structure of the
low-power wireless sensor network is divided into a carrier sense
multiple access-collision avoidance (CSMA-CA) section, which is a
contention access period (CAP) for obtaining a channel based on
contention for connection of a plurality of terminals, and a
guaranteed time slot (GTS) section which is a contention free
period (CFP) for obtaining a dedicated channel without contention.
In the present invention, in order to transmit information measured
in the sensor at high speed, dedicated channels between a sensor
and a router, between a router and a gateway, and between routers
may be configured by utilizing a GTS section.
[0046] FIG. 4 is a diagram illustrating dedicated channel tunneling
between routers, according to an embodiment of the present
invention.
[0047] As illustrated in FIG. 4, respective dedicated channels 210,
220, 230, and 240 may include the path of a lower hierarchy. That
is, the first dedicated channel 210 may bind and use paths of
dedicated channels 210, 220, 230, and 240 of all hierarchies within
the network, and the second dedicated channel 220 may bind and use
paths of the dedicated channels 220, 230, and 240 of all
hierarchies except the path of the dedicated channel 210 between
the gateway 150 and the first router 110. Here, the gateway 150 may
randomly access and control the dedicated channel between
respective routers.
[0048] FIG. 5 is a diagram illustrating a dedicated channel path
setting MAC message, according to an embodiment of the present
invention.
[0049] For example, as illustrated in FIG. 5, a token issuing
message 510 for issuing a fourth token may use a time for notifying
the number (identifier) of the fourth router 140, the number of
sensors 141 and 142 related with the fourth router 140, and the
period of using the GTS mode, as the payload. If the MAC message is
received, the fourth router 140 may set the dedicated channel with
the sensors 141 and 142 and set the time value that uses the GTS
mode.
[0050] Further, a path setting message 520 of the fourth token may
include information for setting the dedicated path between routers.
If the MAC message is received, the fourth router 140 sets the
dedicated channel path between the third router 130 and the fourth
router 140. At the same time, the first router 110, the second
router 120, and the third router 130, which receive the path
setting MAC message, set a dedicated channel between each
corresponding routers and an adjacent router.
[0051] The token returning message 530, which returns the third
token, may include the number of the third router 130, the number
of the fourth router 140, the number of the seventh sensor 131, and
the number of the eighth sensor 132. The router 130, which receives
the MAC message, cancels the dedicated channel with the seventh
sensor 131 and the eighth sensor 132.
[0052] Further, the path canceling MAC message 540 of the third
token includes the path of the third router dedicated channel 230,
and the router 130, which receives the message, cancels the
path.
[0053] FIG. 6 is a flowchart illustrating operation of a gateway,
according to an embodiment of the present invention.
[0054] The gateway issues a token by first transmitting a token
issuing message to the router in order to receive measured
information of sensors, which belong to a specific router, at high
speed (610), and operates a timer (620) so as to monitor whether
there is a response within a given time (630).
[0055] The gateway waits for reception of measured values from
sensors in a state where the time is not terminated (640), and
repeats the process of receiving the measured values from the
entire designated sensors (650). However, when the measured values
are not received from all designated sensors even after the time is
terminated, an abnormal following procedure is performed (660).
[0056] If the measured values are received from al designated
sensors, the gateway continually issues the token (670), and may
receive the measured values of the sensors, which have been
connected all routers, by repeating the process. At this time, when
setting the dedicated channel between routers, the gateway may
encapsulate the dedicated channel path between routers of the lower
hierarchy of the router and transmit the encapsulated path in a
tunneling scheme.
[0057] Likewise, the gateway may integrate the dedicated channel
between routers of the lower hierarchy as well as the dedicated
channel with the first router 110 using the token issuing message
to control the integrated channels.
[0058] FIG. 7 is a flowchart illustrating operation of a router,
according to an embodiment of the present invention.
[0059] The router basically performs communication with sensors at
the contention mode (CAP mode) (710). If the token issuing message
is received from the gateway (720), the router monitors
communication with sensors within a given time by setting the
non-contention mode (GTS) and operating a timer (730) according to
the information of the token issuing message.
[0060] If measured values are received from each sensor, the router
transmits the received measured values to the router of the upper
hierarchy (740). Such a process may be repeated until timer is
terminated or the measured values are received from all sensors
(750 and 760). If the timer has been terminated, but the measured
values are not received from all sensors, the router may perform an
abnormal following procedure (770).
[0061] Further, if a token returning message or a token canceling
message is received from the gateway, the router may perform a
procedure of canceling the dedicated channel with the sensors or
the dedicated channel with the upper routers.
[0062] According to the present invention, information on the
driving state of a railway vehicle may be obtained in real time
through a sensor which is mounted on a driving unit of the railway
vehicle, and thus the safe driving of the railway vehicle may be
secured and the maintenance costs may be minimized.
[0063] Further, according to the present invention, the status
information of the railway vehicle, which is driven in a poor
communication environment, and thus the management of the railway
vehicle may be automated.
[0064] A person having ordinary skill in the art to which the
present invention pertains may change and modify the present
invention in various ways without departing from the technical
spirit of the present invention. Accordingly, the present invention
is not limited to the above-described embodiments and the
accompanying drawings.
[0065] In the above exemplary system, although the methods have
been described based on the flowcharts in the form of a series of
steps or blocks, the present invention is not limited to the
sequence of the steps, and some of the steps may be performed in a
different order from that of other steps or may be performed
simultaneous to other steps. Furthermore, those skilled in the art
will understand that the steps shown in the flowchart are not
exclusive and the steps may include additional steps or that one or
more steps in the flowchart may be deleted without affecting the
scope of the present invention.
* * * * *